1. Field of the Invention
This invention relates to a process for preparing a self-crosslinkable aminosiloxane emulsion, and more particularly, to a process for preparing an aminosiloxane emulsion that is useful as fiber treatment agents, release agents, polishing agents, etc. and that can impart good softness, smoothness, film-forming properties, etc. to textiles.
2. Description of the Prior Art
A method for preparing by emulsion polymerization aminoorganopolysiloxane emulsions having self-crosslinkability which can be used as fiber treatment agents, is known in which a cyclic organopolysiloxane and a trialkoxysilane containing an amino group are subjected to emulsion copolymerization (Japanese Patent Publication (KOKOKU) No. 38609/1981). In this method, an aminoalkyl group that imparts softness, smoothness, etc. to textiles and an alkoxy group that imparts self-crosslinkability to the emulsion are introduced by the trialkoxysilane, and therefore there has been involved the disadvantage that these two properties can not be independently controlled. For example, an attempt to introduce the amino group in a large amount necessarily follows a large amount of the alkoxy group, making the emulsion liable to undergo gelation owing to hydrolysis and condensation.
Also, fiber treatment agents chiefly comprised of aminosiloxane (disclosed in Japanese Patent Publication (KOKOKU) Nos. 1480/1973 and 43617/1979) tend to cause color changes due to the oxidation of aminoalkyl groups contained in the aminosiloxanes adhered to textiles when they are dried by heating in a treatment process or while the textiles are stocked after treatment. In particular, there is seen the so-called "yellowing" phenomenon that a color tone turns yellow if the textiles are of white or pale color types, and thus has been involved a great disadvantage that the commercial value of the textiles that ought to be nearly pure white by nature is lowered.